Summary of this information will be developed annually by the Veterinary Advisor and forwarded to TAG Chair, TAG Pathology Advisor, submitting veterinarians, and the Coraciiformes website.

Necropsy Protocol for Hornbills

This protocol has been drafted to facilitate standard approach to gross pathology evaluation and sample collection for the hornbill group. As a general rule, these birds tend to be long-lived and necropsy opportunities are limited. A summary by body system is provided for sample collection but is only intended to support, not direct, a thorough necropsy. Histopathology samples should be collected into 10% buffered formalin at 1:10 (tissue:formalin). Additional samples are noted throughout the systems for fresh collection and placement into an ultralow freezer (-70 to -80oF). As appropriate, culture lesions found for aerobic, anaerobic, and fungal organisms; organs cultured should have a fresh frozen block collected for future culture or PCR evaluation. Brief discussion is also provided for evaluation of the body system with potential or documented diseases.

External Exam

Photodocumentation of head and casque – lateral (both sides), dorsoventral and ventrodorsal.

Frostbite, trauma, and neoplasia have produced substantial casque damage. In some of these cases, reconstructive surgery of the injured tissues has been attempted. Though graphic publications are available (Birds of the World VI, most recently), it has been noted that exact colorations or conformations may not be available for each species or the individual when these attempts are made. A photo album will be digitally collected and maintained by the Veterinary Advisor of the TAG for distribution to the Chair or housing institutions as needed.

Eight cases of squamous cell carcinoma in the casque of Greater Hornbill (Buceros bicornis) have been reported – punch biopsies of casque lesions as well as normal casque should be collected.

Radiograph of head and casque – lateral (one side), ventrodorsal and rostrocaudal.

Question has arisen on whether sinuses within the casque communicate more deeply and how. This radiographic documentation of adult animals will be the initial undertaking as a photorecord of these structures for comparative purposes.

Strategy to further determine these questions include contrast radiography and advanced imaging (CT) is coordinated through the Veterinary Advisor (see Special Tissue Request).

Head (after radiography)

Oral cavity

Cervical area

Trachea, esophagus (proximal and area of ingluvium), thyroid gland, and parathyroid gland

External body

Plumage, skin, uropygial gland

Collect samples of gland routinely and skin, plumage as found abnormal.

Thoracic Cavity

Lung, heart, and syrinx (intact)

A sterile collection of heart blood (for serum in ultralow freezer) should be made. This will provide bank for heavy metal assay, specifically, iron in potential iron-sensitive species. If this is euthanasia, please collect a 5-10ml sample of blood prior to necropsy for CBC, chemistry panel, and serum bank without heparin, except for CBC.

As these are frequently aged birds, consider that there are lesions in the heart (or on valves) and in the great vessels. Open each of the chambers and lumens to evaluate for arteriosclerotic plaques, endocarditis, and endocardiosis, or neoplastia. Collect samples for these as found into formalin.

A debate exists over the issue of hemochromatosis and hemosiderosis in the Asian hornbills. To evaluate this issue in a standard manner, for all species, minimally please save a 3 cm” square of hepatic parenchyma in an ultralow freezer to evaluate iron concentrations. If possible, a fresh liver sample should be submitted for iron determination at time of necropsy.

Musculoskeletal

Thigh muscle, sciatic nerve, pectoral muscle

Many of these species can become profoundly geriatric. It is best to open all major joints (coxofemoral, stifle, tarsal) on the legs and, as possible, on the wings (shoulder, cubitus, carpal). An evaluation for arthritis should be made and sampling of abnormal joint fluid or synovial tissues. A section of tibiotarsus or ulna should be saved in ultralow freezer (1 cm thick).

Juveniles:

In-Shell Death (less than 50 gm in weight) – open abdomen (ventral slit) and preserve whole in formalin; assess chick’s orientation within the shell on gross necropsy report.

Chicks (immediately post-hatch or 50-100gms in weight) – remove viscera at esophagus and cloaca as a visceral bloc for preservation in formalin, add eye, brain, and muscle

Larger chicks (over 100 gms) or juveniles – follow protocol for adults as much as possible for sample collection. Remember to include yolk sac/umbilicus and bursa for younger birds. Do not submit photos or radiographs of heads or casques – not fully developed or colored as in adults.

NB (frozen samples):These samples should currently be banked at the zoo of origin; if an ultralow freezer is not available, please maintain the fresh tissues refrigerated and contact the Veterinary Advisor within 12 hours of specimen death.